1. Field of the Invention
The present invention relates to a recording device and a method of adjusting laser power.
2. Description of the Related Art
It is necessary for recordable media, such as write-once optical discs and rewritable optical discs, to optimize recording laser power. The optimization process is called optimum power control (OPC) and various methods have been proposed therefor.
Usually, an optical disc is subject to OPC before data is recorded thereon. For example, test data is recorded in a predetermined test area on a disc with varying laser power. The recorded area is reproduced and an evaluation value of a reproduction signal is detected. The evaluation value may include a beta value, a modulation factor, jitter, asymmetry and a symbol error rate.
It is determined on the basis of the evaluation value which laser power might provide the optimum quality of the reproduction signal. Thus, the optimum laser power is determined.
OPC may also be executed during recording.
Japanese Unexamined Patent Application Publication Nos. 2005-259312 and 2005-293689 disclose techniques relating to running OPC.
Japanese Unexamined Patent Application Publication Nos. 2008-77714 and 2006-120281 disclose techniques relating to walking OPC.